Signal.



(1.8. SNAVELY.

SlGNAL.

APPLlCATlON man MAY 2, m4.

PatentedSept 21, 1915 a 1mm.

/ L/A/PL7L Sl-IED SURFACE \NVENTOR WFTNESSES burrito srairns CLARENCE S. SNAVELY, OF EDGEWOOD earner caries.

BOROUGH, PENNSYLVANIA. ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY. OF SVJISSVALE, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

SIGNAL.

Specification of Letters Patent.

Patented Sept. 21, 1915.

Application filed May 2, 1914. Serial No. 885,868.

1 b all "Ur/Lora it "my concern:

Be it known that I, CLARENCE S. SNAVELY, a citizen of the United States, residing at lldgewood Borough, in the county of Allegheny and State of Pennsylvania. have 111- vented certain new and useful Improvements in Signals, of which the following a specilication.

My invention relates to signals, and particularly to railway signals of the type in which sources of light are employed for giving indications.

I will describe one form of signal embodying my invention and will then point out the novel Features thereof in claims.

In the accon'ipanying drawings, Figure l is a view, partly diagrammatic, showing one form of signal embodying my inventmn, and showing also a portion of a railway track along which the beam of light. from the signal is projected. Fig. 2 is a View showing a reflector comprised in the signal shown in Fig. 1.

Referring to Fig. 'l, S designates a signal comprising a source of light L, here shown as being an ineamleseent electric lamp. and a lens 2 for projecting light from the lamp along the railway track ll.

The signal S must be located l'ar enough above the track ll to be clear ot ears and trains. and is prelerably slightly inclined, as shown, so that the axis (l of the ens 2 will intersect the tra k Ill about the point t'arlhesl. l'rom the signal at which it is desirable that the indication, given by the signal shall be clearly distinguishable.

The signal here shown is adapted for use both in daylight and at night, and in order to give indications at long range. in daylight wil houl' requiring excessive power, the signal is so constructed that the direct rays from the lamp ll which strike the lens 2 are' projected tlu-re'lrom in a beam having only a low degrees divergence, thus n'oducmg a slender beam of high candle-power. The upper and lower limits of this beam may be represented by lines4 and 4. It \Vlll be seen, therefore, that as an observer proceeds along the (rack toward the signal from thepoint- 7, this slender beam 4-4 will be visible until he reaches a point Fl at which the lower limit l ol' the beam intersects the track, and that unless other means are provided the light from the signal will be invisible at all locations between point 8 and the signal. In actual practice. when the signal is designed to give indications in daylight as well as at night, the distance between point 8 and the signal from one hundred to three hundred feet. It desirable, however, that the light from the signal should be visible at all locations between the point 8 and a point nearly beneath the.- signal, and to accomplish a continuous indication between these points requires asource of light extending from a pointnear the lamp L to the upper edge of the lens 2. To produce such a source of light I provide a reflector 3 having an opaque, rough, unpolished surface, such for example as a sheet of metal having a surface of unglazed enamel, this reflector being located just outside of the cone whose base is the lens 2 and whose. apex is in the lamp L. This reflector diffuses the light from the lamp L and. reflects the diffused rays to ward the lens 9, by which they are projected in a beam whose limits are approximately delined by lines 5 and 5 Owing to the dill'usion ot the light by the reflector 3, the lens 2 appears to be fully illuminated from all locations on the track between points 8 and 9, and the light is of substantially the same intensity at all locations between these points. Owing to the fact that the reflector 3 not polished and therefore diffuses all light which strikes it, this reflector will not cause the signal to f: lsely appear illuminated when rays of light from an outside source, such as from a locomotive headlight. enter the lens 2. It will be seen that the reflector 3 does not interfere with the rays of light which pass directly from thelamp to the lcns'but that it collects a portion of the light which would otherwise be wasted, and reflects it towa d the lens from which this light is projected to the track between points 10 and 9.

The results secured by a reflector of the kind described cannot be attained by the use of a polished reflector, because the latter would rellect the light in more intense beams at fewer angles, thus giving a beam of smaller spread, and would cause a few bright spots on the lens at several points of observation. Furthermore, a polished reflector would be apt to cause the signal to falsely appear illuminated when ra irom an outside source of light strike the lens.

Having thus described my invention, What I claimis':

1. A signal comprising a source of light, a lens for projecting direct rays from said source for indicating at long range, and a plane reflector located at an angle to said lens and having a light diffusing surface for pro ectin g rays from said source toward said lens for indi ations at short range.

A. signal comprising a source of light, a lens for projecting direct rays from said s I I source for lndioatmg at long range, and a reflector located at an angle to sald lens and having a light diffusing surface for 'PI'I'YJPClZ- ing light from said source toward said lens 1i for indicating at short range.

In testimony whereof I allix my signature in presence of two Witnesses.

CLARENCE SNAVELY.

Witnesses:

i A, HERMAN WEGNE,

\R. L. Krs'rnnn. 

